What's your risk with business plastic?

A company credit card seems like the best of all worlds. You buy something and somebody else pays the bill.

But this is one case where the devil is definitely in the details.

Depending on the card -- or the bank backing the card -- you could be liable for purchases you've made. If the bill comes directly to you, you're probably responsible for late fees and finance charges. And in some circumstances, if the payments are late, it's your credit rating that will suffer.

"Using the company credit card is equivalent to dating the boss's daughter," says Wayne G. Bogosian, managing director of the PFE Group, a financial education firm. "You'd better know what you're doing and not get out of line. Why? Because everything you do will be known and scrutinized. If you mess up, you will lose your job."

Before your boss hands you that shiny new plastic, ask a few questions. First, what's the reimbursement policy? Some companies have centralized billing, which means you charge and all bills are sent to and paid by the company directly.

"Three to four years ago, more and more organizations started moving to centrally billed corporate cards," says David Cramer, a senior vice president with Visa USA.

But in larger companies with hundreds or thousands of employees, some card issuers report that individually billed cards are easier and more popular.

With these, the credit card company sends the bill to you. You pay the bill and get reimbursed.

In the real world, there can be a lag between the charge, when you file your expenses and when you finally get a check. If the credit card bill comes due in the meantime, you may have to dip into your personal account to cover company expenses.

"In many, many companies across the U.S., employers actually see credit cards as a float mechanism," says Bogosian. "That's sort of the reality of an expense account."

Liable for various fees
Or, if you decide to pay the bill late after your expense check comes in, you will likely have to pick up late fees and finance charges out of your own pocket. "Finance charges and late fees are usually not reimbursable," says Bogosian. Some other charges you might have to eat: cash advance fees, over-limit fees and excessive currency-conversion fees.

It's also smart to know what benefits, such as travel or auto rental insurance, come with the card. If you don't know and opt to pay extra for these features, your company could ask that you pay that portion of the bill yourself, he says.

If you or your company is late paying your bill, will that affect your credit rating? That depends on which card you carry, and just how late it is.

"It all boils down to whether the creditor will report that account to your personal [credit] report," says John Ulzheimer, business development manager for MyFico.com, a division of Fair Isaac Corp., the company that developed credit scoring. "In most cases, we don't see it."

"If you're late with payments, typically most issuers do not report the commercial payment experience to credit agencies," says Cramer. "Only if you go terminally bad would there be some type of impact."

With Advanta Corp., one of the largest issuers of business MasterCards, "it should not come back to hurt the credit rating of an employee," says David Weinstock, the company's chief accounting officer.

But it's different with American Express. "It does reflect on your individual credit rating," says Channing Barringer, an American Express representative.

Who's on the hook?
If the worst happens and your company doesn't pay the bill or goes out of business, what happens to the charge slips you've signed?